1. Field of the Invention
The present invention generally relates to a control system for a plurality of electronic apparatus, such as a home bus system and, more particularly, is directed to a signal transmission system.
2. Description of the Prior Art
In recent years, a home bus system has been practically used in homes. This home bus system connects various different electronic apparatus such as, for example, a personal computer, illumination control terminals, gas leakage sensor, and so on, by a transmission cable and makes various controls on the apparatus. In addition, the assignee of the present application has previously proposed the Multi Link System (hereinafter simply referred to as an MLS) in which audio and video informations are distributed through wires from one room of a home to each room where the information can be selectively viewed and listened to. Japanese Patent Laid-Open Gazette No. 2-226890 describes this previously-proposed MLS which will be described below.
Of a plurality of rooms of a house, a basement or a parlor, for example, is used as a master room. Within this master room, a plurality of electronic apparatus, for example, a CD (compact disc) player, a tape cassette deck, a VTR (video tape recorder) or the like, a multi-link center such as a multi-preamplifier or the like to which the electronic apparatus are connected and which controls the same are concentratedly installed. Whereas, multi-link receivers are installed in other rooms through cables in order that audio information and video information from the above-mentioned plurality of electronic apparatus can be listened to and viewed by means of remote controllers. Thus, by operating the remote controller provided in each of the multi-link receivers, it is possible for the user to view and listen to desired informations in each room from various electronic apparatus connected to the multi-link center in the master room.
In the above MLS, when the multi-link center receives control signals from remote controllers from respective rooms substantially at the same time in order for the users in different rooms to listen to and view audio and video informations from a predetermined electronic apparatus installed in the master room, the multi-link center arranges these control signals and transmits in a serial fashion a CD control signal, a tape cassette deck control signal, a VTR control signal, . . . to various electronic apparatus in that order by means of wires. Therefore, in order to process one command (control signal), 100 ms of time is required, and if n users operate their remote controllers within n rooms at a time, respectively, then they can view and listen to audio and video informations 100.times.n ms after the transmission of the commands. Thus, the users are kept waiting for a considerably long period of time.
Furthermore, because an electronic apparatus having no input terminal to receive a control signal through wires cannot receive the control signal from the multi-link center, such kind of electronic apparatus cannot be controlled from each room in a remote-control fashion.